An automatic stopping and restarting device (so-called idling stopping device) of an internal combustion engine is adopted by some types of vehicles in the related art with the aim of improving fuel consumption and reducing environmental burdens. The automatic stopping and restarting device of an internal combustion engine automatically stops the internal combustion engine from running when predetermined automatic stopping conditions are established according to an operation by the driver to decelerate or stop the vehicle while the internal combustion engine is running and also automatically restarts the internal combustion engine when predetermined restarting conditions are established according to an operation by the driver to start or accelerate the vehicle.
As such an automatic stopping and restarting device of an internal combustion engine, a device configured as follows is proposed. That is, in a case where a rotation speed of the internal combustion engine when the restarting conditions are established is higher than a predetermined rotation speed, the internal combustion engine is restarted only by restarting fuel injection, that is, self-restorable restarting is performed whereas when a rotation speed of the internal combustion engine when the restarting conditions are established is lower than the predetermined rotation speed, a starting device (starter) is driven, so that the starting device (starter) is driven less frequently when the internal combustion engine is restarted.
PTL 1 describes that the internal combustion engine is restarted only by restarting fuel injection, that is, self-restorable restarting is performed in a case where a rotation speed of the internal combustion engine when restarting is requested is as high as or higher than a starter necessity determination value which is preliminarily set in consideration of a rotation decrease amount over a range from a crank angle when the restarting is requested to a compression angle position of a combustion cylinder after the restarting is requested.